Dragonfly: RESTORE operations may crash the server

Dragonfly is an in-memory data store built for modern application workloads. Prior to 1.39.0, a crafted RESTORE payload triggers an out-of-bounds read in DragonflyDB's listpack collection loaders, crashing the entire server process (SIGSEGV). Because DragonflyDB requires no authentication by default and RESTORE is a normal keyspace command, an unauthenticated remote attacker can crash the server with a single ~24-byte command — a remote, repeatable denial of service. This vulnerability is fixed in 1.39.0.